package miggy.cpu.instructions;

import miggy.cpu.*;
import miggy.cpu.operands.OperandFactory;
import miggy.SystemModel;
import miggy.api.cpu.*;

/*
//  Miggy - Java Amiga MachineCore
//  Copyright (c) 2008, Tony Headford
//  All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
//  following conditions are met:
//
//    o  Redistributions of source code must retain the above copyright notice, this list of conditions and the
//       following disclaimer.
//    o  Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
//       following disclaimer in the documentation and/or other materials provided with the distribution.
//    o  Neither the name of the Miggy Project nor the names of its contributors may be used to endorse or promote
//       products derived from this software without specific prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
//  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
//  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
//  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
//  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
//  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// $Revision: 21 $
*/
public class MULU implements Instruction
{
	public final void register(InstructionSet set)
	{
		int base = 0xc0c0;
		for(int reg = 0; reg < 8; reg++)
		{
			for(int ea = 0; ea < 64; ea++)
			{
				set.add(base + (reg << 9) + ea, this);
			}
		}
	}

	public final int execute(int opcode)
	{
		Size size = Size.Word;
		Operand src = OperandFactory.fetchOperand((opcode & 0x0038) >> 3, (opcode & 0x007), true, size);
		Operand dst = OperandFactory.dataReg((opcode & 0x0e00) >> 9);

		int srcv = src.get(size);
		int dstv = dst.get(size);
		int result = srcv * dstv;
		dst.put(result, Size.Long);

		if((result & 0x80000000) != 0)
		{
			SystemModel.CPU.setFlag(CpuFlag.N);
			SystemModel.CPU.clrFlag(CpuFlag.Z);
		}
		else
		{
			SystemModel.CPU.clrFlag(CpuFlag.N);

			if(result == 0)
			{
				SystemModel.CPU.setFlag(CpuFlag.Z);
			}
			else
			{
				SystemModel.CPU.clrFlag(CpuFlag.Z);
			}
		}
		SystemModel.CPU.clrFlag(CpuFlag.V);
		SystemModel.CPU.clrFlag(CpuFlag.C);

		int count = 0;
		for(int n = 0; n < 16; n++)
		{
			if((srcv & 0x0001) == 1)
			{
				count++;
			}
			srcv >>= 1;
		}
		return 38 + count;
	}

	public final DecodedInstruction disassemble(int address, int opcode)
	{
		Size size = Size.Word;
		DecodedInstructionImpl di = new DecodedInstructionImpl("mulu", opcode, address, size);
		di.setSrc(OperandFactory.valueOf(address + 2, (opcode & 0x0038) >> 3, (opcode & 0x007), true, size));
		di.setDst(OperandFactory.dataReg((opcode & 0x0e00) >> 9));
		return di;
	}
}
